Drug coated stents or stents that do not have any drug coating (bare metal) are commonly mounted on an angioplasty balloon prior to being inserted into a body cavity. The angioplasty balloon is used to expand the stent and set the stent in position in a body cavity once the stent is positioned in a desired location in the body cavity.
Typically the stent is mounted on the angioplasty balloon by first positioning the angioplasty balloon between the proximal and distal marker bands on the stent so that the angioplasty balloon is properly centered in the interior cavity of the stent. The sent is then crimped to maintain the angioplasty balloon in the stent so that angioplasty balloon is maintained in the proper position in the stent as the stent is positioned in a desired location of a body cavity. The stent may also be crimped to form the body of the stent into a particular shape. Once the stent is properly positioned in the body cavity, the angioplasty balloon is expanded thereby causing the stent to expand. After the stent has been expanded, the angioplasty balloon is deflated and removed from the stent and body cavity.
The positioning of the angioplasty balloon in the stent and the proper crimping of the stent are important to achieve the proper expansion of the stent and the desired performance of the stent. If the angioplasty balloon is not properly positioned in the stent, the stent may not properly expand in the body cavity, thereby increasing the chances of stent failure. If the stent is not properly crimped to maintain the angioplasty balloon in a proper position in the stent as the stent is inserted in a body cavity, the angioplasty balloon may become repositioned in the stent after the stent is crimped and/or as the stent is being inserted in a body cavity. The repositioning of the angioplasty balloon may result in the stent being improperly expanded in the body cavity, thereby increasing the chances of stent failure. If the stent is to be crimped to form the body of the stent in a particular shape, the shape of the body of the stent must be correct after crimping to achieve the desired shape after expansion of the stent; otherwise, an improperly shaped expanded stent may increase the occurrence of stent failure. In addition, the crimping process must be properly performed so as to not damage the stent and/or any coating on the stent. If the stent is damaged, the stent may not properly expand in the body cavity, may break during expansion, may be structurally weakened, and/or the shape of the crimped stent may be adversely altered and interfere with the proper insertion of the stent into a body cavity. A damaged and/or adversely shaped stent thereby increases the chances of stent failure. Many stents are now coated with materials to reduce the rejection of the stent, to reduce in-stent restenosis, to treat a medical condition, and/or for many other or additional reasons. If, during the crimping process, the drug and/or medicine coating on the stent is damaged, the proper amount of drug and/or medication may not be delivered to a body site, thereby possibly increasing the occurrence of stent failure and/or the improper treatment of a body site with the drug and/or medication. Stents are also coated with drugs and/or medications that are time released. The damage to the coating can adversely affect the time during which the drug and/or medication is released, thus increasing the occurrence of stent failure and/or the improper treatment of a body site with the drug and/or medication. If a coating on the stent is used to reduce rejection of the stent, the damage to such coating can result in increased occurrences of stent failure.
Although the proper mounting of the angioplasty balloon in the stent is very important to the success of the stent being inserted in a body cavity, the present day practice is to merely visually inspect the stent after the angioplasty balloon has been inserted in the stent to determine if the angioplasty balloon has been properly positioned in the stent and that the stent has been properly crimped. Several automated devices have been developed to crimp the stent in order to increase the uniformity of the final crimped stents and to reduce the occurrence of improperly crimped stents. These crimped stents that are formed by such automated devices are typically visually inspected to ensure that the crimped stent has not been significantly damaged during the crimping process. Thereafter, the stent is packaged for use. Detailed information concerning the crimped stent is not available or is difficult to obtain by a physician prior to the stent being inserted into a human or animal.
In view of the present state of the art, there is needed a method and apparatus for inspecting a stent to determine if an angioplasty balloon has been properly inserted in a stent, to determine that the stent has been properly crimped, and/or to determine that the stent and/or coating on the stent has not be damaged. There is also a need in the art for a method and apparatus for tracking the information pertaining to the stent and the crimping of the stent so that better informed decisions can be made to use a particular stent to thereby increase the success rate of an inserted stent.